content: /*
   * Copyright 2011-2016 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package ix;
  
  import java.util.Iterator;
  
  final class IxAggregate<T> extends IxSource<T, T> {
  
      final IxFunction2<T, T, T> aggregator;
  
      IxAggregate(Iterable<T> source, IxFunction2<T, T, T> aggregator) {
          super(source);
          this.aggregator = aggregator;
      }
  
      @Override
      public Iterator<T> iterator() {
          return new AggregateIterator<T>(source.iterator(), aggregator);
      }
  
      static final class AggregateIterator<T> extends IxSourceIterator<T, T> {
  
          final IxFunction2<T, T, T> aggregator;
  
          AggregateIterator(Iterator<T> it, IxFunction2<T, T, T> aggregator) {
              super(it);
              this.aggregator = aggregator;
          }
  
          @Override
          protected boolean moveNext() {
              Iterator<T> it = this.it;
              IxFunction2<T, T, T> f = aggregator;
  
              if (it.hasNext()) {
                  T acc = it.next();
                  while (it.hasNext()) {
                      acc = f.apply(acc, it.next());
                  }
                  value = acc;
                  hasValue = true;
                  done = true;
                  return true;
              }
              return false;
          }
      }
  
  }
  